diff --git a/process_maps.py b/process_maps.py
index def9ac4..95586de 100755
--- a/process_maps.py
+++ b/process_maps.py
@@ -14,15 +14,16 @@ if __name__ == '__main__':
 	current_timestamp = datetime.datetime.now().strftime('%Y%m%d-%H%M')
 	
 	parser = argparse.ArgumentParser()
-	parser.add_argument('--map-list', action='store')
+	parser.add_argument('--map-list', action='append')
 	#TODO: Add argument to pass path to osmosis
 	#TODO: Add argument to pass path to output dir
 	args = parser.parse_args()
 
 	map_list = []
-	with open(args.map_list, 'r') as maps:
-		for line in maps:
-			map_list.append(line.strip())
+	for alist in args.map_list:
+		with open(alist, 'r') as maps:
+			for line in maps:
+				map_list.append(line.strip())
 
 	print('Creating working directories')
 	if not os.path.exists('out'):